Although combustible liquids have higher flash points than flammable liquids, they can pose serious fire and/or explosion hazards when heated.

Flammable Liquid Classifications

Any liquid having a flashpoint below 100 deg. F (37.8 deg. C) or higher, the total of which make up 99 percent or more of the total volume of the mixture. Flammable liquids shall be known as Class I liquids. Class I liquids are divided into three classes as follows:

Any liquid having a flashpoint at or above 100 deg. F (37.8 deg. C). Combustible liquids shall be divided into two classes as follows:

Class II - shall include those with flashpoints at or above 100 F (37.8 C) and below 140 F (60 C), except any mixture having components with flashpoints of 200 F (93.3 C) or higher, the volume of which makes up 99 percent or more of the total volume of the mixture.

Class III - shall include those with flashpoints at or above 140 F (60 C).

Class III liquids are subdivided into two subclasses:

Class IIIA - shall include those with flashpoints at or above 140 F (60 C) and below 200 F (93.3 C), except any mixture having components with flashpoints of 200 F (93.3 C), or higher, the total volume of which makes up 99 percent or more of the total volume of the mixture.

Class IIIB - shall include those with flashpoints at or above 200 F (93.3 C).

Physically connect two conductive objects together with a bond wire to eliminate a difference in static charge potential between them.

You must provide a bond wire between containers during flammable liquid filling operations, unless a metallic path between them is otherwise present

Grounding

Eliminates a difference in static charge potential between conductive objects and the ground.

Although bonding will eliminate a difference in potential between objects, it will not eliminate a difference in potential between these objects and earth unless one of the objects is connected to the earth with a ground wire.